Fuel pump



July 21, 1925.

O. MADER FUEL PUMP 2 Sheets-Sheet 1 Filed June 29, 1920 EMMA": M

July 21, 1925. 1,546,596

0. MADER FUEL PUMP Filed June 29, 1920 2 Sheets-Sheet 2 'IIIIIul/f'lllllllllll Em/0mm Patented July 21, 1925;

1,546,596 UNITED STATES- PATENT- OFFICE,

. one man, or ns'ssau, GERMANY, 'assrcnoa TO nuco commas, or nrssnu,

' GERMANY.

FUEL PUMP.

Application filed June 29, 1920. Serial no. 892,831.

To all whom it may canoe m:

Be it known that I, Orro MADER, a c1t1- zen of the German Empire, residing at Dessau,-Germany, have invented certain new and useful Improvements in Fuel Pumps (for which I have filed application in Germany, April 4, 1917, Patent No. 312,878; Austrla, February 11, 1918; Hungary, February 28, 1918; Sweden, January 13, 1920; Norway,

January 26. 1920; Denmark, January 28v 1920), of which the following is a specification.

My invention relates to fuel pumps for internal combustion engines and more especially to devices. for simultaneously packing and lubricating the guldes of mov ng parts of fuel pumps for internal combustlon engines, which are intended to convey nonlubricating liquids, such as petrol-or the like, which dissolve lubricants.

The use of such fuel pumps, which are to convey petrol and similarnon-lubricating fluids, has hitherto been connected with considerable difiiculty, which rendered a permanent and reliable operation of 'thepumps doubtful. This difficulty is mainly due to the fact that the lubricating oil conveyed to the gliding surfaces is dissolved by petrol and washed off, so that very'soon the same conditionswill occur as in a dry state, es-

pecially quick wear and tear and danger of,

sticking. Moreover, the slight surface-tension of petrol in the case of slight leakage of p the guides will result in a considerable loss of liquid and irregularities in the supply, thereby causing great trouble in operating the engine.- These difliculties -will increase with the pressure, against which the pumps are intendedto convey, and'the more at:- cu'rately the quantity of fuel to be supplied per stroke is to be measured. "Inuview of these difliculties, fuel pumps'for the disper sion and introduction of fuel immediately into the working cylindenfor internal com bustion engines have generally been aban cloned, although by using pumps a far better dispersion, a more uniform composition of the mixture and a simpler regulation isen-y sured than with carburetters. p p In accordance with the present invention,

now, the drawbacks hitherto experienced with petrol pumps or the like are obviated by producing such a high and permanently uniform or rhythmically varyingpressure infjcating fluid by connecting the piston 2 of "the pump with a step-piston 19. The stepa space filled with lubricating fluid, inwhich nstance, the

the non-lubricating fluid. .,fi1led with lubricating'fluid;

the guides of the moving part, which is to be packed and lubricate ends at the side averted from the working space of the pump,

that this mean pressure is higher than that of the non-lubricating fluid to be conveyed. In this operation, the lubricating fluid has the tendency to move in the guide or packimportance from an economical point ofview either.

In accordance with this invention the new arrangement may be so developed that the lubricating oil under not only for lubricatlng and packing the pressure can be used guides but also for moving such parts of the engineasare working in non-lubricating fluid, for instance pistons of pumps. valves or the like? furthermore for regulating this motion according to distance and time, for

instance in the case of pumpsfor varying the quantity to be conveyed and the time of conveyance.

In the drawingsaflixcd to this specificamodifioations of a fuel pump embodying my invention are illustrated by way of example. In the drawings I 1 Figs. 1-4 are longitudinal pumps with .stepped pistons.

Referring to the drawings, 1 is the casing of a pump, 2 the moved part of the engine, which works in non-lubricating fluid, for

piston of a pump; 3 is the space filled with non-lubricating fluid;4, is the pipe supplying such fluid; 5, is the suctionsections of fuel valve loaded with the spring 6; 7 is the pressure-valvewithspring 8-, and 9 the pressure,

pipe of the pump; 12 is a crank-gear for drlving a piston producing the pressure in 14 is the space connecting the space 14 with areservoir 16.

tion and forming part thereof different 15 is a pipe for Figs. 1 to 4 show pumps,in which a pressure varying in harmony with the V strokes-of the pump is produced in the lubrisurface works in the. annular space 14, which is filled with lubricating fluid.

If, according to Fig. 1, the piston moves to the right, the lubricating fluid in the space 14 is conveyed through the overflowvalve 21 loaded with a spring 22, through .the channel 20, thereby entering the reser- In order to ensure the pressure of the lubricating fluid in the space 14 during the conveying stroke to be higher, than that of the non-lubricating fluid in the space 3, the overflow-valve, wh1ch is constructed to form a piston 21, may be exposed to the pressure of bothfluids through pipes 20, 25, as shown in Fig. 1. In that case, the spring22 offers a certain excess safety for the pressure of the lubricating fluid. .The piston 21 may be replaced by a diaphragm or the like.

Fig. 2 shows an arrangement similar to that shown in Fig. 1 with the modification that, in place of the loaded overflow-valve 21, a throttling screw 26 is used, which can be so regulated that the mean pressure of the lubricating fluid within the space 14 exceeds that of the non-lubricating fluid which is to be conveyed. This arrangement is to be recommended whenever the pump discharges the fluid through a mouth-piece (nozzle) 50, since, in that case, the pressures in the fluid to be conveyed as well as in the lubricating fluid bear almost the same proportion at all numbers of revolution, so that the screw 26 need not be readjusted for each number of revolutions.

In the modification of the pump without suction-valve as illustrated in the drawings the quantity to be conveyed may be easily regulated by displacing the dead centres of the piston 2.

Fig. 3 shows the same arrangement as Fig. 2, with the modification that the principle underlying the present invention of conveying lubricating fluid to the guides of such parts of the engine as are operating in non-lubricating fluid, is also applied to the pressure valve 7, which is here shown as being guided with a spindle 45 in a bore 27 of the piston 2. The space 27 is connected with the space 14 containing the lubricating fluid by means of the bore 28, so that the valve spindle guide is permanently lubricated. The pressure occuring in the non-lubricating fluid during the conveying gtroke assists inopening the pressurefvalve 'fannu ar space 14 containing the lubricating fluid through the annular spaces 31, 32.and the channel 33, so that it is lubricated and tightened in the same manner as the guide of the piston 2.

It is obvious that the arrangement may be such that,.by providin steps and using specia throttling screws, the slide itself will place under pressure the oil required for its own lubrication and packing. I

In the place of step-pistons, special pis tons, moved rhythmically and in unison with the piston of the pump (valves, slides), may be used, so as to produce a rhythmically varying pressure in the lubricating fluid.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

I claim: 1

l. A liquid fuel pump comprising in combination, a pump cylinder, a piston in said cylinder, mechanical means for causing reciprocating motion of said piston in said cylinder and means for forcing lubricant under an average pressure exceeding the average pumping pressurein between the outer end of said piston and said cylinder.

2. A liquid fuel pump comprising in combination, a pump cylinder, a piston a portion of which projects from said cylinder, mechanical means for causing reciprocating motion of said piston in said cylinder, means for surrounding the portion of said piston which projects from said cylinder with lubricant and means for placing such lubricant under an average pressure exceeding the avcrage pumping pressure.

3. A liquid fuel pump comprising in combination, a pump cylinder, a piston a portion of which projects from said cylinder, mechanical means for causing reciprocating motion of said piston in said cylinder, means for surrounding'the portion of said piston, which projects from said cylinder, with lubricant and throttling means for placing such lubricant under an average pressure exceeding the average pumping pressure.

4. A liquid fuel pump comprising in combination, a stepped pump cylinder, a stepped piston, mechanical means for causing reciprocating motion of said piston in said cylinder, means for supplying liquid fuel into the narrow part of the cylinder, means for supplying lubricant into the wider part of said cylinder and means associated with said lubricant suppl ing means for creating in the wider part 0 said cylinder an averthe slide 30 with age pressure exceeding the average pumping pressure.

5. A liquid fuel pump comprising in combination, a stepped pump cylinder, a stepped piston, mechamcal means for causing reciprocating motion of said piston in said cylinder, means for supplying liquid fuel into the narrow part of said cylinder, means for su plying lubricant into the wider part of said cylin er and an adjustable throttling means associated with said lubricant supplying means for creating in the wider part of sald cylinder an average pressure exceeding the average pumping pressure.

6. A liquid fuel pump comprising in com bination, a stepped pump cylinder, astepped piston, mechanical means for causing reciprocating motion of said piston in said 0 linder, means for supplying liquid .fuel into the narrow part of said cyllnder, a conduit comprising a plurality of branches for supplying lubrlcant into the wider part of sald cylinder, one branch of said conduit leading to a point near the narrower part of said cylinder, another branch to a farther remotetherefrom and a throttling means in the former branch for creating in the wider part of said cylinder an average pressure exceeding the average pumping pressure. v

7. A liquid fuel pump comprising in combination, a stepped pump cylinder, a stepped piston, mechanical means for causing reciprocating motion of said piston in said cylinder, means for supplying liquid fuel into the narrow part of said. cylinder, a conduit comprising a plurality of branches for supplying lubricant into the wider part of said cylinder, one branch of said conduit leading to a point near the narrower partof said cylinder, another branch to a oint farther remote therefrom and a throttling means in the former branch for creating in the wider part of said cylinder an average pressure exceeding the average pumping pressure, said throttling means being arranged to be acted upon also by the pumping pressure.

8. A liquid fuel ump comprlsing in combination, a steppe pump cylinder,astepped point the narrow part of said cylin er, a conduit for supplyin lubricant into the wider part of said cylin er, one branch of said conduit comprising a plurality of branchesleadin to a point near the narrower part of said cylinder, another branch to a point farther remote therefrom and a loaded non-return valve in the first mentioned branch. 9. A liquid fuel pump comprising in combination, a stepped pump cylinder, a stepped piston, mechanical means for causin reciprocating motion of said piston in sai cylinder, means for supplying. liquid fuel into the narrow part of said cylinder, a conduit comprising a plurality of branches for supplyin lubricant into the wider art of said cylin er, one branch of said con uit leadin to a point near the narrower part of sai cylinder, another branch to a point farther remote therefrom, a loaded non-return valve in the first mentioned branch and 'a connection between the loaded side of said valve and the narrower part of said cylinder.

10. A liquid fuel pump comprising in combination, a stepped pump cylinder, a stepped piston, mechanical means for causing reciprocating motion of said piston in said cylinder, means for supplying liquid fuel into the narrow part of said cylinder,

a conduit comprising a plurality of branches for supplying lubricant into the wider art of said cylinder, one branch of said con uit leading to a point near the narrower part of said cylinder, another branch to a point farther remote therefrom, a valve inserted in said fuel sup lying means and surrounded by an annu ar space, a connection between the former of said branches and said annular space and a throttling means in said former branch for creating in the wider part of said cylinder and in said space an average pressure exceeding the average pumping pressure.

In testimony whereof I afiix in Si OTTO ature. ER. 

